GWD31-2中数学题求教，感觉答案不对啊

littleshrimp

Q23:答案选A,我选的C
AMOUNT OF BACTERIA PRESENT

Time	Amount
1:00 P.M.	10.0 grams
4:00 P.M.	x grams
7:00 P.M.	14.4 grams

Data for a certain biology experiment are given in the table above.If the amount of bacteria present increased by the same fraction during each of the two 3-hour periods shown, how many grams of bacteria were present at 4:00 P.M.?



A.12.0

B.12.1

C.12.2

D.12.3

E.12.4

Answer: A

yxbrent

设 fraction 为 1/a  
10*(1+1/a)=x
x*(1+1/a)=14.4

两未知数，两个方程
我算出来X=12